Evolution of the Electric Drive Train

This figure shows the progression for Toyota from first launching the Prius hybrid in 1997 in Japan, to launching the Mirai in 2015. "Prius" means "forerunner", "Mirai" means "future"  All the electric drivetrain components had to be proven along the way as they were critical to being able to launch the ultimate objective (the fuel cell electric vehicle (FCEV)).       

The FCEV is the ultimate goal in EV drive train evolution, to meet society's expectations for rapid transfer of large amounts of energy (as hydrogen) from grid to vehicle and range of 300 - 500 miles. The hydrogen is a store of energy that can be made via rapid response electrolysis systems at times when electricity is in surplus, is lowest cost and greenest, via grid balancing demand-side response services.                                                                                                   

Decarbonising energy and transport, whilst offering the ultimate in no compromise, zero carbon, zero NOx, zero SOx, zero particulate emissions for driver freedom!

I can only reproduce part of the figure from 2007 model, happy to send complete (from 1997) if anyone interested.